The present invention relates to an ice breaker. Various different ice breaker constructions are known. In the case of an ice breaker with self-propulsion, the forward propulsion takes place by means of the propeller or screw. An ice breaker operating in shallow waters has ever increasing difficulties in removing the broken ice with decreasing distance from the ship's bottom to the ocean, sea or river bed and inter alia the broken ice disturbes the supply of water to the propellers.
Ice floes which have become broken and move laterally by the ship's prow under the unbroken ice cover laterally limit the fairway channel formed and surround the stern of the ice breaker in such a way that the ice is drawn into the propellers as a result of the increased water speed produced by the propeller thrust deduction and the ice is chopped by said propellers, so that an increased propeller power is required. With increased propeller thrust deduction further disadvantageous effect occur, namely the ocean bed is washed out by the backwash and is moved to the rear and side if the ocean bed is made from soft material, so that protuberances and depressions form on said bed, which lead to navigational problems, particularly for ships following the ice breaker or in the case of sternway travel of the actual ice breaker. In addition, the propellers can be damaged by the ice flows broken by the prow during forward propulsion and moved back by the thrust deduction into the fairway channel.